U.S. Sets 136.52% Preliminary Antidumping Margin on Chinese Tin Mill Products – What Coated-Steel Buyers Should Check

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On September 21, 2026, the U.S. Department of Commerce published a preliminary affirmative less-than-fair-value (antidumping) determination on tin mill products from the People’s Republic of China (Case A-570-228, Doc 2026-19274, 91 FR 59760). Commerce preliminarily assigned the China-wide entity a weighted-average dumping margin of 136.52%, with a cash deposit rate of 130.17% after adjustment for subsidy offsets, and it preliminarily found that critical circumstances exist. The investigation covers the period October 1, 2025 through March 31, 2026.

Tin mill products are not a finished machined part, but they are a bought-in flat-rolled substrate. They are the coated steel that stamping, drawing, forming and light machining lines turn into welded and drawn packaging, enclosures, shielding, battery and connector hardware, and cable armoring tape. When a preliminary duty reaches triple digits on that input, cost, availability and origin documentation move from a trade-press headline into a purchasing and engineering checklist.

What Commerce Actually Determined

  • Case: A-570-228, applicable September 21, 2026 (signed September 16, 2026).
  • Margin: China-wide entity at 136.52% weighted-average dumping margin; 130.17% cash deposit rate adjusted for subsidy offsets.
  • Basis: facts available with adverse inferences. Commerce found that no respondent qualified for a separate rate, so no producer/exporter combination rates were calculated, and all named producers fall into the China-wide entity.
  • Critical circumstances: preliminarily affirmative, which means suspension of liquidation reaches unliquidated entries made on or after the date 90 days before publication of the notice – not only entries going forward.
  • Timing: a final determination is due no later than 75 days after the signature date of the preliminary determination, with a U.S. International Trade Commission injury phase to follow if the final is affirmative.

Commerce reached a parallel preliminary affirmative countervailing duty result on the same product on September 15, 2026 (Doc 2026-18792, 91 FR 58418), with an estimated subsidy rate of 66.61% ad valorem for the Shougang entities and all others. That companion case explains why the 136.52% dumping margin becomes a lower 130.17% cash deposit: the deposit is the margin reduced by subsidy pass-through found in the CVD proceeding. Buyers should read the two numbers as one combined trade-remedy position, not two independent ones.

The Scope Boundary Is the Practical Part

The scope covers tin mill flat-rolled products coated or plated with tin, chromium or chromium oxides – that is, tinplate and tin-free steel (also called electrolytic chromium-coated steel, or ECCS). Coverage is broad on purpose: all thicknesses, widths, forms in coils or cut sheets, electrolytic or other coating, trimmed or untrimmed edges, coating thicknesses, surface finishes, tempers, single- or double-reduced material, and whether or not the product is plastic-coated.

There is exactly one carve-out, and it is narrow. Excluded is certain single-reduced electrolytically chromium-coated steel tape used as an armoring and shielding layer for fiber-optic and telecommunications cables, commonly called copolymer coated steel tape – and only if it satisfies all seven listed conditions:

  • Single-reduced electrolytically chromium-coated steel;
  • Actual thickness of 0.160 mm or less (55-pound base box weight);
  • Type MR steel;
  • T2-T3 temper;
  • Tensile range of 45-57 KSI (310.20-393.00 MPa);
  • Minimum 15% elongation;
  • Chromium coating of 0.06-0.12 g/m2.

A product that misses any one of those seven points is not excluded. That matters to cable-shielding and electronics buyers because ECCS tape is often treated as a commodity grade: two suppliers can both call their material “copolymer coated steel tape” while only one falls inside the exclusion. The written scope description, not the trade name and not the HTSUS number, controls.

Tariff classifications named in the notice run through HTSUS 7210.11.0000, 7210.12.0000, 7210.50.0020, 7210.50.0090, 7212.10.0000 and 7212.50.0000 for non-alloy steel and 7225.99.0090 and 7226.99.0180 for alloy steel. Commerce repeats the standard caution that these subheadings are for convenience and customs purposes only.

Why This Reaches a Precision Manufacturing Buyer

  • Coated flat stock is a controlled input, not a commodity. Tinplate and ECCS are specified by coating weight, temper and reduction because those drive formability and corrosion behaviour. A duty that reshapes the supply base can push parallel imports into the market, and parallel material is where coating-weight and temper control drift.
  • Critical circumstances shorten the reaction window. Retroactive suspension reaching back 90 days means a shipment in transit, or an order placed before the notice, may carry exposure the buyer did not price in. This is a documentation exercise, not a market-timing one.
  • Origin is now a drawing-level question. For coated-steel components, the melt-and-pour country and coating origin belong with the material certificate. A country-of-origin statement is a purchasing control when the substrate carries a preliminary duty at this level.
  • Quotation shelf life shortens. Where an input can carry a duty measured in tens to over a hundred percent, a quote on stamped or drawn coated-steel parts ages faster than the tooling or machining cycle suggests.

Practical Verification Actions

  • Check scope membership per line item. Identify whether each bought-in coated steel is tinplate or ECCS (in scope) versus a genuinely different product, and test each shielding or armoring tape against all seven exclusion criteria rather than against the supplier’s product name.
  • Trace melt-and-pour and coating origin. Record the producing mill, country of melt and pour, and the exporter of record for each heat. A structured RFQ validation checklist is a reasonable place to hold that material evidence before it is needed under time pressure.
  • Qualify a documented second source. A supplier qualification record should capture origin and the current material channel, so re-sourcing does not begin from zero.
  • Read the trade-remedy pattern across steel lines. The same publication carried a final CVD order on Algerian steel wire rod, and earlier steel and aluminium tariff-relief rules remain relevant to primary-metal importers. Reviewing origin across all steel line items, not only those in one notice, is the cheaper approach.
  • Budget for documentary latency. Re-qualified origin statements and new certificates take weeks before the first part is produced. Buyers re-routing supply should build that time into the programme schedule.

Limited Conclusions

What is established and dated: on September 21, 2026, Commerce published a preliminary affirmative antidumping determination on tin mill products from China (91 FR 59760, Doc 2026-19274, A-570-228) with a 136.52% China-wide margin, a 130.17% cash deposit rate after subsidy offsets, and a preliminary affirmative finding of critical circumstances, over an October 1, 2025 to March 31, 2026 period of investigation. A companion CVD preliminary determination published September 15, 2026 set a 66.61% subsidy rate. A final determination is due within 75 days of the preliminary signature date, and interested parties may still file comments and request a hearing.

A preliminary determination is not a final one, and it is not the same as a definitive duty. For precision manufacturing buyers, the practical message is narrower than the headline rate: most machined components do not contain in-scope tin mill products, and the single scope exclusion is real but narrow. But coated flat-rolled steel is a shared upstream input, and trade-remedy exposure attaches to the producer, the coating origin and the country of origin – not to the shop that forms the final part. Keeping origin, coating specification and material documentation aligned with the drawing remains the least expensive control in coated-steel sourcing.

References

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